Computing games, such as games played on a PC or on a games console, often involve avatars. Avatars represent the player in a game, and are often designed to the taste of the player. The avatar may be more or less anthropomorphic, thereby increasing the level of involvement and identification the player has with his/her virtual representation in the game. The appearance and performance of the avatar in the game may evolve during the game, for example if the avatar loses health, picks up objects, gains strength etc.
In such games, it is generally an objective to make the player feel as part of the gaming world as possible. The control of the avatar in a game is usually achieved by the player using a handheld input device, such as a control pad, and some gaming consoles also come equipped with other inputs such as foot pedals, which can to some extent match actions in the real world performed by a player to actions of the avatar in the game, and thereby improve the playing experience.
However, there exists a technical problem in improving the interaction between the player's environment and the game environment. In particular, computer games generally do not encourage a great deal of physical activity, and the player's health can become an issue.